Evaluation of the xTAG Gastrointestinal Pathogen Panel Assay for the Detection of Enteric Pathogens in Kuwait.

OBJECTIVE: To evaluate the utility of the Luminex xTAG gastrointestinal pathogen panel (GPP) assay in the detection of enteric pathogens from diarrheal stool samples in Kuwait. MATERIALS AND METHODS: The Luminex xTAG GPP assay was used according to the manufacturer's instructions to evaluate single diarrheal stool samples from 109 hospitalized patients at Mubarak Al-Kabeer Hospital, Kuwait, from March 2014 to June 2015. The assay procedure involved nucleic acid extraction from stool samples, amplification of the target by reverse transcriptase polymerase chain reaction, hybridization of the amplified target by probe, detection of the target by the Luminex instrument and computerized data analysis. Conventional microbiological assays were used as the gold standard for comparison. RESULTS: From the 109 diarrheal stool samples, 20 (18.4%) pathogens were detected by the xTAG GPP assay compared to 10 (9.2%) pathogens using conventional assays. Both methods detected 3 Salmonella spp., 3 Clostridium difficile, 2 rotavirus and 2 norovirus. In addition, the xTAG GPP assay detected 1 Shigella sp., 6 Campylobacter spp., 1 Cryptosporidium sp. and 2 Giardia lamblia which were missed by conventional assays. CONCLUSIONS: In this study, xTAG GPP detected twice as many pathogens as the conventional assays. We recommend the introduction of this assay in routine diagnostic laboratories for a rapid and better diagnosis and treatment of diarrheal disease.

Sequence analysis of genes mediating extended-spectrum beta-lactamase (ESBL) production in isolates of Enterobacteriaceae in a Lagos Teaching Hospital, Nigeria.

BACKGROUND: Extended-spectrum ß-lactamases (ESBLs) in Gram-negative organisms is now a major concern in Enterobacteriaceae worldwide. This study determined a point-prevalence and genetic profiles of ESBL-producing isolates among members of the family Enterobacteriaceae in Lagos State University Teaching Hospital Ikeja, Nigeria. METHODS: Consecutive non-repetitive invasive multidrug-resistant isolates of the family Enterobacteriaceae obtained over a period of 1 month (October 2011) were studied. The isolates were identified using VITEK-2/VITEK MS Systems. Susceptibility testing was performed using E test technique; results were interpreted according to the criteria recommended by the Clinical and Laboratory Standards Institute (CLSI, 2012). ESBL production was detected by E test ESBL method and confirmed by polymerase chain reaction (PCR). RESULTS: During the one-month study period, 38 isolates with ESBL phenotypic characteristics were identified and confirmed by PCR. Of these, 21 (55.3 %) were E. coli, 12 (31.6 %) K. pneumoniae, 3 (7.9 %) Proteus spp., 1 (2.6 %) each M. morganii and C. freundii. Thirty (79 %) harbored bla CTX-M genes. Sequence analysis revealed that they were all bla CTX-M-15 genes. Twenty-nine (96.7 %) of these, also harbored bla TEM genes simultaneously. All the CTX-M-15-producing isolates carried insertion sequence bla ISEcP1 upstream of bla CTX-M-15 genes. The E. coli isolates were genetically heterogeneous, while the K. pneumoniae had 98 % homology. CONCLUSIONS: Our point-prevalence surveillance study revealed a high prevalence of Enterobacteriaceae isolates harboring bla CTX-M-15 in the Hospital. Urgent implementation of antibiotic stewardship and other preventive strategies are necessary at this time in our hospital.